s3c24xx中断的操作

@ File：head.S
@ 功能：初始化，设置中断模式、系统模式的栈，设置好中断处理函数
@******************************************************************************

.externmain
.text
.global _start
_start:
@******************************************************************************
@ 中断向量，本程序中，除Reset和HandleIRQ外，其它异常都没有使用
@******************************************************************************
bReset

@ 0x04: 未定义指令中止模式的向量地址
HandleUndef:
bHandleUndef

@ 0x08: 管理模式的向量地址，通过SWI指令进入此模式
HandleSWI:
bHandleSWI

@ 0x0c: 指令预取终止导致的异常的向量地址
HandlePrefetchAbort:
bHandlePrefetchAbort

@ 0x10: 数据访问终止导致的异常的向量地址
HandleDataAbort:
bHandleDataAbort

@ 0x14: 保留
HandleNotUsed:
bHandleNotUsed

@ 0x18: 中断模式的向量地址
bHandleIRQ

@ 0x1c: 快中断模式的向量地址
HandleFIQ:
bHandleFIQ//一共有8个

Reset:
ldr sp, =4096@ 设置栈指针，以下都是C函数，调用前需要设好栈
bldisable_watch_dog@ 关闭WATCHDOG，否则CPU会不断重启

//初始化必须做的事情关闭watchdog设置栈指针

msr cpsr_c, #0xd2@ 进入中断模式
ldr sp, =3072@ 设置中断模式栈指针

msr cpsr_c, #0xdf@ 进入系统模式
ldr sp, =4096@ 设置系统模式栈指针，
@ 其实复位之后，CPU就处于系统模式，
@ 前面的“ldr sp, =4096”完成同样的功能，此句可省略

/ /进入各种模式在于设置栈指针

blinit_led@ 初始化LED的GPIO管脚

blinit_irq@ 调用中断初始化函数，在init.c中
msr cpsr_c, #0x5f@ 设置I-bit=0，开IRQ中断

ldr lr, =halt_loop@ 设置返回地址//调用main函数前的工作
ldr pc, =main@ 调用main函数
halt_loop:
bhalt_loop

HandleIRQ:
sub lr, lr, #4@ 计算返回地址
stmdbsp!,{ r0-r12,lr }@ 保存使用到的寄存器
@ 注意，此时的sp是中断模式的sp
@ 初始值是上面设置的3072

ldr lr, =int_return@ 设置调用ISR即EINT_Handle函数后的返回地址
ldr pc, =EINT_Handle@ 调用中断服务函数，在interrupt.c中
int_return:
ldmiasp!,{ r0-r12,pc }^@ 中断返回

#include "s3c24xx.h"

#define GPB5_out(1<<(5*2))// LED1
#define GPB6_out(1<<(6*2))// LED2
#define GPB7_out(1<<(7*2))// LED3
#define GPB8_out(1<<(8*2))// LED4

#define GPG11_eint(2<<(11*2))// K1,EINT19
#define GPG3_eint(2<<(3*2))// K2,EINT11
#define GPF2_eint(2<<(2*2))// K3,EINT2
#define GPF0_eint(2<<(0*2))// K4,EINT0

void disable_watch_dog(void)
{
WTCON = 0;// 关闭WATCHDOG很简单，往这个寄存器写0即可
}

void init_led(void)
{
GPBCON = GPB5_out | GPB6_out | GPB7_out | GPB8_out ;
}

void init_irq( )
{
GPFCON= GPF0_eint | GPF2_eint;
GPGCON= GPG3_eint | GPG11_eint;

// 对于EINT11、19，需要在EINTMASK寄存器中使能它们
EINTMASK &= (~(1<<11)) & (~(1<<19));


PRIORITY = (PRIORITY & ((~0x01) | (0x3<<7))) | (0x0 << 7) ;

// EINT0、EINT2、EINT8_23使能
INTMSK&= (~(1<<0)) & (~(1<<2)) & (~(1<<5));
}

#include "s3c24xx.h"

void EINT_Handle()
{
unsigned long oft = INTOFFSET;
unsigned long val;

switch( oft )
{
// K4被按下
case 0:
{
GPBDAT |= (0x0f<<5);// 所有LED熄灭
GPBDAT &= ~(1<<8);// LED4点亮
break;
}

// K3被按下
case 2:
{
GPBDAT |= (0x0f<<5);// 所有LED熄灭
GPBDAT &= ~(1<<7);// LED3点亮
break;
}

// K1或K2被按下
case 5:
{
GPBDAT |= (0x0f<<5);// 所有LED熄灭

// 需要进一步判断是K1还是K2，或是K1、K2被同时按下
val = EINTPEND;
if (val & (1<<11))
GPBDAT &= ~(1<<6);// K2被按下，LED2点亮
if (val & (1<<19))
GPBDAT &= ~(1<<5);// K1被按下，LED1点亮

break;
}

default:
break;
}

//清中断
if( oft == 5 )
EINTPEND = (1<<11) | (1<<19);// EINT8_23合用IRQ5
SRCPND = 1< INTPND = 1< //清除的顺序
}

int main()
{
while(1);
return 0;
}

s3c24xx.h

#defineWTCON(*(volatile unsigned long *)0x53000000)

#defineMEM_CTL_BASE0x48000000
#defineSDRAM_BASE0x30000000

#define NFCONF(*(volatile unsigned int*)0x4e000000)
#define NFCMD(*(volatile unsigned char *)0x4e000004)
#define NFADDR(*(volatile unsigned char *)0x4e000008)
#define NFDATA(*(volatile unsigned char *)0x4e00000c)
#define NFSTAT(*(volatile unsigned char *)0x4e000010)

#define GPBCON(*(volatile unsigned long *)0x56000010)
#define GPBDAT(*(volatile unsigned long *)0x56000014)

#define GPFCON(*(volatile unsigned long *)0x56000050)
#define GPFDAT(*(volatile unsigned long *)0x56000054)
#define GPFUP(*(volatile unsigned long *)0x56000058)

#define GPGCON(*(volatile unsigned long *)0x56000060)
#define GPGDAT(*(volatile unsigned long *)0x56000064)
#define GPGUP(*(volatile unsigned long *)0x56000068)

#define GPHCON(*(volatile unsigned long *)0x56000070)
#define GPHDAT(*(volatile unsigned long *)0x56000074)
#define GPHUP(*(volatile unsigned long *)0x56000078)

#define ULCON0(*(volatile unsigned long *)0x50000000)
#define UCON0(*(volatile unsigned long *)0x50000004)
#define UFCON0(*(volatile unsigned long *)0x50000008)
#define UMCON0(*(volatile unsigned long *)0x5000000c)
#define UTRSTAT0(*(volatile unsigned long *)0x50000010)
#define UTXH0(*(volatile unsigned char *)0x50000020)
#define URXH0(*(volatile unsigned char *)0x50000024)
#define UBRDIV0(*(volatile unsigned long *)0x50000028)

#define SRCPND(*(volatile unsigned long *)0x4A000000)
#define INTMOD(*(volatile unsigned long *)0x4A000004)
#define INTMSK(*(volatile unsigned long *)0x4A000008)
#define PRIORITY(*(volatile unsigned long *)0x4A00000c)
#define INTPND(*(volatile unsigned long *)0x4A000010)
#define INTOFFSET(*(volatile unsigned long *)0x4A000014)
#define SUBSRCPND(*(volatile unsigned long *)0x4A000018)
#define INTSUBMSK(*(volatile unsigned long *)0x4A00001c)

#define EINTMASK(*(volatile unsigned long *)0x560000a4)
#define EINTPEND(*(volatile unsigned long *)0x560000a8)